How to work with the atlas

L. Herrmann and K. Vennemann (view photo).

Introduction

The aim of this atlas is to supply maps and data to all kind of users for their work concerning Niger and Benin. The atlas has to be seen as a dynamic, interactive system which is under continuous development and to which external contributions are desired. In order to fulfil this objective special structures and technical solutions were developed which shall be introduced in the following to ease the work with the atlas (sample map).

Technical minimum requirements

In order to allow access to a wide public the atlas is designed for use with a 14' monitor. Java scripts are included, thus internet browser like Netscape 3.0 or Internet Explorer 3.0 or higher versions are necessary. Please enable Java applications. The atlas is best viewed with screen specifications 32768 colours and 800*600 pixel resolution (known problems).
 

Webpage elements

The elements are self explaining. In the case you use a monitor >14' you can enlarge the atlas frame for a better view and set the map legends aside the main frame.  You can directly reach the comments without viewing the maps via the comment button. Please note that the "legend" button will always open the legend of the first map in the project (via java script). Legends of additional maps will appear when opening the respective map  (known problems).

Maps

Maps in the internet atlas will have a projection depending on their geographical extent:

Overview maps showing Niger and Benin as a whole unit on one map have - unless indicated differently - the following projection specifications:

maps showing parts of these regions (unless indicated differently):


Data

Source data available under paragraph 9 of the map comments are provided in ArcView shape format (ESRI) and therefore consist of three files (*.shp, *.shx, and *.dbf). For more information on these formats please consult ESRI software reference books or the internet site www.esri.com. For flexible and easy use the provided source files have the following projection specifications: not projected; stored in decimal degrees (dd); Spheroid: Clarke 1880. In ArcView use of these files is easy: They are loaded unprojected and therefore can easily be displayed or printed in all projections available in ArcView (projection on the fly). To do this the projection must be set under the menu point View/ Projection.

Metadata:

Documentation of metadata for the source data ("data about data" - that means information about the origin of the data and accuracy) will be provided as a text file. If metadata are not completely available a text file with the available information will be provided and marked to be incomplete. The metadata file will contain:

All these information files are included as text files in one zip-file per project  and can be downloaded via internet browser.
 

Comments

Map comments (link to scientific approach) are organised like short communications with additional web-features (links, pictures, etc.).

Language

In order to reach a broader public, especially in the countries concerned, the comment section of the atlas is provided in English and French. However, the maps are produced only as an original version either in english or in french, as creating bilingual versions would have been too time consuming.
 

Known problems

Comments
Navigating from the "Comments (direct links to map comments) " - page to the projects using the drop down menus: This does not work twice for the same project when returning to this page using the back button of your browser. To reach the same  project again select the first entry of the respective dropdown menu  (either "overview" for part A , "Niger" for part B for "Benin" for  part C, depending in which part the project is located), and then select the project you like to open again.

Language
The map language might not match the language in the documentation you are using, since maps are produced only as an original  version either in English or in French, as creating bilingual versions would have been too time consuming.

Legends
Please note that the "legend" button  will open the legend of the first map (map one) in the project (via Java script).
Legends  belonging to additional maps will appear when opening the respective map. When clicking on the map or scrolling after the first  appearance of the  legend it "disappears" (It is still there but behind the map window). For map one you can bring it to the front  again using the legend button. For maps other than map one,  you have to use the "reload" button of your web browser to bring the  respective legend in front. If a legend does not appear also use the reload button. To avoid that the legend will "disappear" in the  background when clicking accidentally on the map, resize your browser window and position the main window and the legend window  side by side on your screen.

Using Arc View project files
The *.apr files are in Arc View 3.1 format and cannot be read with Arc View 3.0 (unless converted to 3.0 format inside Arc View 3.1  using an avenue script  available on the ESRI homepage). When opening the project file it will ask you to locate all the GIS files and  table files used in the project. After going through this sometimes arduous procedure you should save the project again before  closing it to avoid having to go through this process again.  Another option is to edit the Arc View project file using an text editor: simply open the project file (*.apr) and replace the paths for all  files used in the project with the current directory path where the files are located on your computer. The easiest way to replace all  paths is to use the "search and replace" function of your text editor: Search for     e:/nocheins/data/     and replace the whole path (everything except the file name) with the current directory path on your  computer. Then save the project file under a different name (however the ending should stay .apr) and open it with Arc View. If you have Arc View 3.0 and cannot read the included project files please use the legend files (*.avl) for certain themes to reproduce the map.

Web browser compatibility
Best compatibility with  Java scripts was obtained using Netscape Navigator 4.5 or higher versions. Version 3.0 of MS Internet  Explorer does not fully support Java scripts included in the atlas. This results in message windows indicating Java script errors. These  messages can be avoided during the session by checking the box in the pop-up  window " ignore Java script errors on this page"  when the first "Java script error" is indicated.

Missing software and tools ?
On the CD-ROM the following freeware and shareware programs are included (on the internet goto links for download)
Please respect the copyright regulations.